Basically the plot goes like this (As far as I can remember). The Earth is discovered by a group of Galactic civilizations, and is encouraged to join.
We begin to download massive amounts of information from the different civilizations, and as the story goes on, the main character (whom I believe is an ambassador for the human race) discovers that it is all a sham, and that we are part of a giant galactic poker game, with the losers being "retired", i.e. exterminated, and the information is the poker chips in the game, and we are accumulating obligations for each piece of information.